>>12886725phrased in terms of general relativity, the surface of earth is flat in the sense that the gravitational field is roughly constant over the entire surface. The "earth" as "we" know it (humans have never gone deeper than ~20 miles into the crust) is a flat surface embedded in a spherical space because of the way massive objects bend spacetime.
Note that this is an entirely useless semantic convolution for almost all practical purposes. It doesn't change the fact that the earth is still round in the sense that if you start from any point on earth and travel in any direction along the surface, you'll eventually end up where you started. A globe is still the most accurate mental picture for people who can't think in four dimensions. The accelerating sheet model is inaccurate because there are paths along the surface which are straight that don't meet up back where they started.
